Whistle



FIG. 1 is a top plan view of a whistle, showing my new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a side elevational view thereof;

FIG. 4 is an elevational view of the opposite side thereof;

FIG. 5 is a front elevational view thereof;

FIG. 6 is a rear elevational view thereof;

FIG. 7 is a perspective view thereof. 

The ornamental design for a whistle, as shown and described. 